Speed control baffle for use in a hydraulic-rotary drilling system

Abstract

A baffle device for use in a drilling sub assembly, the baffle device including an upper chamber for receiving a drilling fluid, the upper chamber having a window through which the drilling fluid exits the upper chamber, the window being in fluid communication with a fluid channel forming a groove on an outer surface of the baffle, the fluid channel having an exit though which the drilling fluid exits the baffle. In general, the exit of the fluid channel is aligned with a downstream turbine unit, such that the turbine unit is rotated by the drilling fluid exiting the baffle. The present invention further includes various modifications to control the velocity at which the drilling fluid exits the baffle.

1 . A baffle device for use in a drilling sub assembly, the baffle device comprising:
 an outer surface having a profile selectively shaped to compatibly insert within an outer casing of a drilling sub assembly;   a first end having an upper chamber for receiving an upstream drilling fluid, a perimeter of the upper chamber being defined by a vertical wall, the upper chamber further having a bottom surface that is oblique to the vertical wall;   a window formed in the vertical wall, the window providing an outlet to the upper chamber;   a fluid channel forming a groove on the outer surface of the device, the fluid channel having a first section forming a portion of the window, the first end section being in fluid communication with the upper chamber, the fluid channel further having a second section extending to a second end of the device; and   a fluid channel exit forming an outlet to the fluid channel, the fluid channel exit being positioned approximate to the second end of the device, wherein a drilling fluid exits the upper chamber through the window and flows through the fluid channel to exit the device through the fluid channel exit.   
     
     
         2 . The device of  claim 1 , further comprising a lower chamber forming a portion of the second end of the device, the lower chamber compatibly and rotatably receiving a turbine unit of the drilling sub assembly. 
     
     
         3 . The device of  claim 1 , wherein the fluid channel comprises a plurality of fluid channels. 
     
     
         4 . The device of  claim 1 , wherein the window comprises a plurality of windows. 
     
     
         5 . The device of  claim 1 , wherein the window comprises dimensions to prevent passage of a debris present within the drilling fluid. 
     
     
         6 . The device of  claim 1 , further comprising a wire mesh screen inserted within the upper chamber to cover the window and thereby prevent passage of a debris through the window. 
     
     
         7 . The device of  claim 1 , wherein the upper chamber comprises a nadir at which the drilling fluid experiences aberrant currents. 
     
     
         8 . The device of  claim 1 , wherein the fluid channel is linear. 
     
     
         9 . The device of  claim 1 , wherein the fluid channel is curved. 
     
     
         10 . The device of  claim 1 , wherein the fluid channel is branched. 
     
     
         11 . The device of  claim 1 , wherein the fluid channel is tapered. 
     
     
         12 . The device of  claim 1 , wherein the fluid channel exit is angled such that the drilling fluid contacts a downstream turbine unit at an angle from approximately 1° to about 90°. 
     
     
         13 . A method for controlling the rotational speed of a drill bit used in a hydraulic-rotary drilling system, the method comprising:
 providing a baffle having an upper chamber for receiving a drilling fluid, the upper chamber having a window through which the drilling fluid exits the upper chamber, the window being in fluid communication with a fluid channel forming a groove on an outer surface of the baffle, the fluid channel having an exit through which the drilling fluid exits the baffle;   positioning the baffle upstream from a turbine unit such that the exit of the baffle is aligned with a blade of the turbine unit; and   angling a portion of the fluid channel such that the drilling fluid exits the baffle to contact the blade of the turbine unit at an angle from approximately 1° to about 90°.   
     
     
         14 . The method of  claim 13 , further comprising tapering the fluid channel to modify the velocity at which the drilling fluid flows through the fluid channel. 
     
     
         15 . The method of  claim 13 , further comprising branching the fluid channel. 
     
     
         16 . The method of  claim 13 , wherein the window comprises a plurality of windows. 
     
     
         17 . The method of  claim 13 , wherein the fluid channel comprises a plurality of fluid channels. 
     
     
         18 . A modular baffle system, comprising:
 a tubular chamber member having an upper rim surface, a bottom rim surface, and a wall surface therebetween, the bottom rim surface being in a first plane that is generally oblique to the wall surface;   a window forming a notch in the bottom rim surface and the wall surface; and   a base portion having a top surface to support the bottom rim surface of the tubular chamber, the base portion further having a fluid channel forming a groove on an outer surface of the base portion, the top surface being in a second plane that is equal to the first plane, wherein the window and the fluid channel are aligned by seating the tubular chamber member on the base portion in the first plane.   
     
     
         19 . The system of  claim 18 , further comprising a plurality of fluid channels. 
     
     
         20 . The system of  claim 18 , further comprising a plurality of windows.